Apparatus for chamfering tablets

ABSTRACT

An apparatus for chamfering the sharp circumferential edges of tableted article. The apparatus has a rotating disk rotatably mounted on a stationary frame and having a grinding or abrading surface which is sufficiently hard and rough to scrape the tablets. A guiding member which is disposed above said surface, is composed of two end working segments and an intermediate segment having a plurality of grooved channels extending over the full length of the guiding member. The grooved channels are provided with inlets and outlets for the tablets at opposite ends of the channels, said channels being opened towards said grinding or abrading surface. Portions of each of said grooved channels which correspond to both of said working segments have a crosssection permitting unobstructed passage of the tablets while holding them oriented in a predominantly upright yet slightly inclined position with one of the sharp circular edges being directed towards the surface of the disk. A portion of each of said channels which corresponds to said intermediate segment is twisted in the direction of its length to change the orientation of the tablets from the position where one of its edges rests against the grinding or abrading surface to the position where the other edge rests against the grinding or abrading surface. These channels also have a somewhat narrowed but deepened and continuously changing cross-section to smoothly permit said change of tablet orientation.

United States Patent 11"] Saeki 1 *Oct. 15, i974 Inventor: Haruji Saeki,Osaka, Japan Notice: The portion of the term of this patent subsequentto June 13, 1990, has been disclaimed.

[22] Filed: June 30, 1972 [21] Appl. No.: 268,106

[30] Foreign Application Priority Data Mar. 29, 1972 Japan 47-31353 [52]U5. El. 51/128, 29/76 [51] int. Cl B24b 7/00, 823d 67/00 [58] Field ofSearch 51/128, 129, 130, 110, 51/116,112, 210,215 E, 215 M, 289 S, 289R; 29/76, 78

[56] References Cited UNITED STATES PATENTS 3,182,428 5/1965 Hannon51/289 R X 3,348,338 10/1967 Messerschmidt 51/130 X 3,561,164 2/1971Dunn t 51/116 3,668,751 6/1972 Saeki 51/128 X Primary Examiner-AlLawrence Smith Assistant Examiner-Nicholas P. Godici Attorney, Agent, orFirm-Stewart and Kolasch, Ltd.

[57] ABSTRACT An apparatus for chamfering the sharp circumferentialedges of tableted article. The apparatus has a rotating disk rotatablymounted on a stationary frame and having a grinding or abrading surfacewhich is sufficiently hard and rough to scrape the tablets. A guidingmember which is disposed above said surface, is composed of two endworking segments and an intermediate segment having a plurality ofgrooved channels extending over the full length of the guiding member.The grooved channels are provided with inlets and outlets for thetablets at opposite ends of the channels, said channels being openedtowards said grinding or abrading surface. Portions of each of saidgrooved channels which correspond to both of said working segments havea cross-section permitting unobstructed passage of the tablets whileholding them. oriented in a predominantly upright yet slightly inclinedposition with one of the sharp circular edges being directed towards thesurface of the disk. A portion of each of said channels whichcorresponds to said intermediate segment is twisted in the direction ofits length to change the orientation of the tablets from the positionwhere one of its edges rests against the grinding or abrading surface tothe position where the other edge rests against the grinding or abradingsurface. These channels also have a somewhat narrowed but deepened andcontinuously changing cross-section to smoothly permit said change oftablet orientation.

15 Claims, 7 Drawing Figures ii: i

1 APPARATUS FOR CHAMFERING TABLETS BACKGROUND OF THE INVENTION 1. Fieldof the Invention The present invention generally relates to an apparatusfor preparatory treatment of tableted articles. More particularly, itconcerns an apparatus for scraping sharp circumferential edges of thetablets formed by a tableting press as a thickset cylinder optionallywith spherical ends, to improve the shape of such tablets so that theyare more like ellipsoids or spheres.

Preferably, tablets, in general, are shaped such that each has anexternal form which resembles a sphere or an ellipsoid with a roundedsperical edge which facilitates coating with sugar or cellulosicmaterial after they are molded.

2. Description of the Prior Art The circumstances surrounding the wellknown prior art devices for tablet manufacture are very undesirable.Since tablets have hitherto been manufactured by the conventionallyknown tableting press of the punchand-die type, the shapes of the formedtablets are generally such that each is composed of a side cylindricalwall which corresponds to the internal wall of the die cavity and topand bottom convex end walls which correspond to the concave operativeheads of the punches. The lines along which said cylindrical wallintersects with the sphereical end walls, constitute rather sharpterials as sugars subsequent to the compacting process,

manufacturers have been compelled to perform the coating operation byadding an additional thickness of the coating layer to fill up saidgroove between the banks. This operation requires excessive coatingmaterials and prolongs processing time. Obviously, the abovecircumstances can equally be applicable to the case of film coatingwith, for example, cellulosic materials and the like.

It is therefore essential that the tablet which is to be coated has ashape wherein its sharp circular edges have been removed or at least thesharpness of the edge lines have been reduced. It order to fulfil theserequirements there has hitherto been proposed a method wherein theshapes of the concave operative heads of the punches are modified so asto have a compound concave shape composed of a double or multiplesphere. According to this method, however, the construction of thepunches become very complicated with a consequent high production and/ortooling cost of the punches and shortening of the sevice life of thepunches.

SUMMARY OF THE INVENTION It is therefore the primary object of thepresent invention to provide an apparatus for removing or at leastreducing the sharpness of the circumferential edges of the tabletedarticles as much as possible and allowing the shapes of such tablets toapproach those of a sphere or an ellipsoid.

It is another object of the present invention to provide an apparatusfor a preparative treatment interposed between a compacting process anda coating process in the tablet manufacture, which apparatus is capableof minimizing the thickness of the material utilized for coating thetablets.

BRIEF DESCRIPTION OF THE DRAWINGS These and other objects of the presentinvention and attendant advantages thereof will be made apparent tothose who are conversant with the art to which the present inventionpertains by following the detailed disclosure of the specification andthe appended claims, taken in conjunction with the accompanyingdrawings.

In the following paragraphs, description will be given in conjunctionwith the drawings wherein the parts or components having identical orcorresponding functions are designated by the same or similar referencecharacters or numerals throughout the several views of the sameapparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the presentinvention, there is provided an apparatus for chamfering tabletedarticles comprising; a stationary frame, rotating disk rotatably mountedon said stationary frame and having a grinding or abrading surface whichis sufficiently hard and rough to scrape the tablets, a means fordriving said disk, and a guiding member disposed above said surface,being composed of two working segments with an intermediate segmentdisposed therebetwecn and having a plurality of grooved channelsextending over the full length of the guiding member with inlets andoutlets for the tablets at opposite ends of the channels and openedtowards said grinding or abrading surface. Portions of each of saidgrooved channels which correspond to both of said working segments havea cross-section permitting unobstructed passage of the tablets whileholding the tablets oriented in a predominantly upright yet slightlyinclined position with one of the sharp edges of the tablet beingdirected towards the surface of the disk. A portion of each of saidchannels which corresponds to said intermediate segment is twisted inthe direction of its length to change the orientation of the tabletsfrom the position where one edge of the tablet rests against thegrinding or abrading surface to the position where the other edge of thetablet rests against the grinding or abrading surface. The channels inthe intermediate segment have a somewhat narrowed but deepened andcontinuously changing cross-section to smoothly permit said change ofthe orientation. A bracket is mounted on said stationary frame forholding said guiding member.

As the grinding or abrading surface of the present invention, grindingmembers, of hard stainless steel or tool steel treated with hard chromeplating, are generally preferred, although any roughened surfaces havingsufficient hardness and ruggedness for scraping the circumferentialedges of the compacted tablets can be employed.

The guiding member of the present invention is disposed closely abovethe grinding or abrading surface of the rotating disk, allowing a smallclearance between them, which clearance is finely adjustable by aholding bracket fixedly mounted on the stationary frame. The guidingmember is composed of an integral body of functionally differentiatedthree segments, Le, a first working segment, an intermediate segment anda second working segment.

Each of the grooved channels formed on the guiding member and openedtowards the grinding or abrading surface is one which is capable ofholding the tablet in a generally upright but somewhat inclined postureor status, or in other words, holding the tablet in a generally uprightposition with a moderate angle of inclination with respect to thegrinding or abrading surface. Thus either one or the other of thecircular edges of the tablets is always in good contact with saidsurface in both of its working segments.

Although the angle of orientation of the tablet may not be specificallyrestricted and may be varied with the original shape of the tablet solong as the sharp circular edges of the tablets can effectively bescraped during the transferring through the grooved channel, an anglebetween about and 40, preferably. one between about 20 and 35, withrespect to a line perpendicular to the grinding or abrading surface isdesirable for effective production and convenience of toolmg.

Furthermore, the angle of orientation may be varied over the length ofthe channel to obtain a rounded edge. However, it is usually fixed forthe convenience of tooling, and even in the case of a fixed orientation,a satisfactory result can be obtained because of the small clearancebetween the tablet and the side walls of the grooved channel.

Since such orientation must conform to the posture or status of thetablets in order to make the tablets follow the moving grinding orabrading surface, or in other words, to cause the tablets to be draggedby the surface, the inclination of the portion of each of the groovedchannels which corresponds to the first working segmentof the guidingmember must be opposite to that which corresponds to the second workingsegment.

Therefore. a portion of each of the grooved channel which corresponds tothe intermediate segment must be twisted in the direction of its lengthand have a somewhat narrowed but deepened and continously changingcross-section so that the angle of orientation of the travelling tabletis reversed within this portion.

Portions of each of the grooved channels which correspond to the bothworking segments must be capable of transferring said tabletstherethrough in a direction which intersects the derection of movementof the grinding or abrading surface at an angle other than a rightangle. This angle of intersection is very important because itdetermines the component force due to the rotational movement of thegrinding or abrading surface with which the tablets are in contact andexerted on the tablets. Therefore, an angle between about and 50,preferably one between about and 45 has been found to be particularlyeffective.

Furthermore, since the even transferring of the successively fed tabletsis desirable from a production standpoint, this angle of intersectionmay preferably be constant over the full length of the grooved channelused for chamfering.

Therefore, each centerline of the grooved channels may preferably bespirally contoured so that they intersect, at every point whichconstitute the centerline, with tangents of the every circles whichconstitute the disk at a given angle, even through a simple straightline may optionally be used.

Usually, the apparatus of the present invention is used together with atablet aligning means which is integrally annexed to the first workingsegment at the inlet portion of the grooved channels and including aplurality of twisted'tunnels. The purpose and/or function of this meansis to feed the tablets into the grooved channels by first evenlyaligning the randomly stuffed or scattered tablets and then errectingthem during their travels within the twisted tunnels.

Moreover, these major components of the apparatus including the aligningmeans may preferably be tilted in order to insure the smoothtransferring of the tablet through the grooved channels and tunnels,particularly through those within the aligning means and theintermediate segment of the guiding member. The angle of such tiltingwith respect to the horizontal plane may be larger than about 45,preferably larger than about In FIG. 1, wherein the essential componentsof the present invention are shown, rotating disk 1 is mounted on astationary fame (F of FIG. 5) and has a grinding or abrading surface 12disposed over the full surface thereof except on a mounting portion 11of the core. The disk is rotatably driven in the direction of the arrowby a driving means (not shown).

A guiding member 5 is disposed above said grinding or abrading surface12 and is held in this position by a bracket (not shown) which can befixedly mounted on the stationary frame. The clearance between themember 5 and the surface 12 is adjustable by said bracket. The member 5is an integral body of the functionally classifiable three segments;namely, a first working segment 51, an intermediate segment 52 and asecond working segment 53.

The guiding member 5 also has five grooved channels 61, 62-65 (indicatedgenerally by broken lines except the cut-out portions) which equallyopen toward said grinding or abrading surface 12 and run substantiallyparallel with each other, extending through the respective segments 51,52 and 53 from inlets for the tablets 71, 72-75 at the end of the firstworking segment 51 to outlets 81, 82-85 at the opposite end of thesecond working segment 53.

Each centerline of the grooved channels 61, 62-65 is preferably spirallycontoured, within both of the working segments 51 and 53, so that itintersects, at every point which constitutes the centerline, with thetangents of every circle which constitutes the disk at approximately 40.Although a portion of each centerline which corresponds to theintermediate segment 52 of the guiding member 5 may be a straight linefor connecting both curved portions which correspond to working segments51 and 53, it may preferably be a gradual curve for smoothly connectingboth of said curved portions as shown in the drawing.

The cross-section of each of the grooved channels 61, 62-65, within theportions of the both working segments 51 and 53, is so designed that itpermit unobstructed passage of the tablet while holding the tabletsoriented in a predominantly upright yet slightly inclined (about withrespect to a line perpendicular to the grinding or abrading surface)position with one of its sharp edges inclined towards the surface 12 ofthe disk 1 as specifically shown in the sectional views of FIGS. 2 and4, where the tablets are inclined in opposite directions.

As previously described, since that portion of each of the groovedchannels 61, 62-65 which corresponds to the intermediate segment 52 ofthe guiding member 5 is designed to connect together those portions ofsaid channels which correspond to the working segments 51 and 53 and tohave the ability of reversing the angle of orientation of the tabletswith respect to the grinding or abrading surface 12 during theirconveyance through this portion, said portion must be twisted in thedirection of its length.

Therefore, this portion of each of the grooved channels 61, 62-65 isdesigned to have a somewhat narrowed but deepened and continuouslychanging crosssection. This facilitates errecting the tablets from theiroriented postures and then inclining them from their upright postures totheir oppositely oriented postures, as best shown in the sectional viewsof FIGS. 3a through Be.

A tablet aligning means 9 integrally annexed to the first workingsegment 51 of the guiding member 5, includes five twisted tunnels 91,92-95, which run substantially parallel with each other and are adaptedto communicate with the grooved channels 61, 62-65, re-

spectively when combined together. The tunnels 91,-

92-95 permit unobstructed passage of the tablet T introduced therein atinlets 101, 102-105 and provide for the smooth feeding ofthe tablet intothe grooved channels 61, 62-65 in their substantially upright postures.

The tablet T introduced into the grooved channels 61, 62-65 at theinlets 71, 72-75, is transferred through the grooved channels whichcorrespond to the first working segment 51 in the direction indicated bythe arrow receiving a component force due to the rotational movement ofthe grinding or abrading surface 12 with which the tablet T is incontact, the particular circular edge ofthe tablet which is in contactwith the surface 12 being scraped or bevelled during this transferringoperation.

The tablet T is then pushed into the portion of each of the groovedchannels which corresponds to the intermediate segment 52 where itsangle of orientation is reversed. When the tablet T is switched fromthis portion to the next portion of each of the grooved channels whichcorresponds to the second working segment 53, its other circular edge isscraped while being transferred along this portion. Finally the tabletis expelled from one of the outlets 81, 82-85.

As can be appreciable from the perspective view of FIG. 5, a plane ofthe essential part of the apparatus including the annexed tabletaligning means 9 is actually tilted forward with respect to thehorizontal plane at about a 60 angle. Therefore, the tablet can be eventransferred smoothly by the aid of gravity through such portions as thetunnels of the aligning means and the portions of the grooved channelswhich correspond to the intermediate segment, where no component forcedue to the rotating movement of the grinding or abrading surface isexerted on the tablets.

The tablets processed and expelled from the outlet 81, 82-85 in thepreviously described manner, now have a shape which is more like anellipsoid because the circular edges are evenly chamfered andsmoothened. When a tablet has been treated as hereinabove described, anysubsequent treatment of the tablet, such as for example a coatingoperation, will be extremely simplified.

The present invention may be embodied in other specitic forms withoutdeparting from the spirit or essential attributes thereof and,accordingly, reference should be made to the appended claims as well asthe foregoing specification as indicating the scope of the invention.

What is claimed is:

1. An apparatus for chamfering the sharp edges of tableted articles,comprising; a stationary frame, a rotating disk rotatably mounted onsaid stationary frame and having a grinding or abrading surface which issufficiently hard and rough to scrape the tablets; a means for drivingsaid disk; a guiding member disposed above said surface, being composedof a working segment on each side of an intermediate segment and havinga plurality of grooved channels extending over the full length of theguiding member with inlets and outlets for the tablets at opposite endsof the channels, said channels being opened towards said grinding orabrading surface, with portions of each of said grooved channels whichcorrespond to both of said working segments having a cross-sectionpermitting unobstructed passage of the tablets while holding the tabletsoriented in a predominantly upright yet slightly inclined position withone of the sharp edges being directed towards the surface of the disk,and a portion of each of said channels which corresponds to saidintermediate segment being twisted in the direction ofits length tochange the orientation of the tablets from a position where one edge isdisposed against the grinding or abrading surface to a position wherethe other edge is disposed against the surface, said intermediatesegment having a somewhat narrowed but deepened and continuouslychanging cross-section to smoothly permit said change of orientation;and a bracket mounted on said stationary frame for holding said guidingmember.

2. An apparatus as claimed in claim 1, wherein the cross-section of theportions of each grooved channel which correspond to the workingsegments are formed so that the angle of said orientation of the tabletsheld by said grooved channel is from about 20 to about 40 with respectto a line perpendicular to the grinding or abrading surface.

3. An apparatus as claimed in claim 2, wherein said angle of orientationhas a fixed value between about 20 and 40.

4. An apparatus as claimed in claim 2, wherein said angle of orientationis continuously changing along its length within the range between about20 and 40.

5. An apparatus as claimed in claim 2, wherein said angle of saidorientation has a fixed value between about 25 and 35.

6. An apparatus as claimed in claim 2, wherein said angle of orientationis continuously changing along its length within the range between about25 and 35.

7. An apparatus as claimed in claim 1, wherein each center line of thegrooved channel is spirally contoured within the working segments sothat it intersect, at all the points which constitute the center line,with tangents of all the circles which constitute the disk at asubstantially constant angle other than a right angle.

8. An apparatus as claimed in claim 7, wherein said constant angle ofintersection is selected from an angle between about 30 and about 50.

9. An apparatus as claimed in claim 7, wherein said constant angle ofintersection is selected from an angle 13. An apparatus as claimed inclaim 1, wherein said plurality of the grooved channels runsubstantially parallel with each other throughout the guiding member.

14. An apparatus as claimed in claim 1, wherein the apparatus is usedtogether with a tablet aligning means which is integrally annexed to thefirst working segment at the inlet portion of the grooved channels andwhich comprises a plurality of twisted tunnels which are capable offeeding the tablets into the grooved channels by first evenly aligningthe randomly stuffed or scattered tablets and then errecting them duringtheir travels within the twisted tunnels.

15. An apparatus as claimed in claim 1, wherein said bracket for holdingsaid guiding member is capable of adjusting the clearance between theguiding member and the abrading surface or the disk.

1. An apparatus for chamfering the sharp edges of tableted articles,comprising; a stationary frame, a rotating disk rotatably mounted onsaid stationary frame and having a grinding or abrading surface which issufficiently hard and rough to scrape the tablets; a means for drivingsaid disk; a guiding member disposed above said surface, being composedof a working segment on each side of an intermediate segment and havinga plurality of grooved channels extending over the full length of theguiding member with inlets and outlets for the tablets at opposite endsof the channels, said channels being openEd towards said grinding orabrading surface, with portions of each of said grooved channels whichcorrespond to both of said working segments having a cross-sectionpermitting unobstructed passage of the tablets while holding the tabletsoriented in a predominantly upright yet slightly inclined position withone of the sharp edges being directed towards the surface of the disk,and a portion of each of said channels which corresponds to saidintermediate segment being twisted in the direction of its length tochange the orientation of the tablets from a position where one edge isdisposed against the grinding or abrading surface to a position wherethe other edge is disposed against the surface, said intermediatesegment having a somewhat narrowed but deepened and continuouslychanging cross-section to smoothly permit said change of orientation;and a bracket mounted on said stationary frame for holding said guidingmember.
 2. An apparatus as claimed in claim 1, wherein the cross-sectionof the portions of each grooved channel which correspond to the workingsegments are formed so that the angle of said orientation of the tabletsheld by said grooved channel is from about 20* to about 40* with respectto a line perpendicular to the grinding or abrading surface.
 3. Anapparatus as claimed in claim 2, wherein said angle of orientation has afixed value between about 20* and 40*.
 4. An apparatus as claimed inclaim 2, wherein said angle of orientation is continuously changingalong its length within the range between about 20* and 40*.
 5. Anapparatus as claimed in claim 2, wherein said angle of said orientationhas a fixed value between about 25* and 35*.
 6. An apparatus as claimedin claim 2, wherein said angle of orientation is continuously changingalong its length within the range between about 25* and 35*.
 7. Anapparatus as claimed in claim 1, wherein each center line of the groovedchannel is spirally contoured within the working segments so that itintersect, at all the points which constitute the center line, withtangents of all the circles which constitute the disk at a substantiallyconstant angle other than a right angle.
 8. An apparatus as claimed inclaim 7, wherein said constant angle of intersection is selected from anangle between about 30* and about 50*.
 9. An apparatus as claimed inclaim 7, wherein said constant angle of intersection is selected from anangle between about 35* and about 45*.
 10. An apparatus as claimed inclaim 1, wherein a plane including the rotating disk and the guidingmember is tilted forward with respect to the horizontal plane.
 11. Anapparatus as claimed in claim 10, wherein said angle of tilting isgreater than about 45*.
 12. An apparatus as claimed in claim 10, whereinsaid angle of tilting is greater than about 55*.
 13. An apparatus asclaimed in claim 1, wherein said plurality of the grooved channels runsubstantially parallel with each other throughout the guiding member.14. An apparatus as claimed in claim 1, wherein the apparatus is usedtogether with a tablet aligning means which is integrally annexed to thefirst working segment at the inlet portion of the grooved channels andwhich comprises a plurality of twisted tunnels which are capable offeeding the tablets into the grooved channels by first evenly aligningthe randomly stuffed or scattered tablets and then errecting them duringtheir travels within the twisted tunnels.
 15. An apparatus as claimed inclaim 1, wherein said bracket for holding said guiding member is capableof adjusting the clearance between the guiding member and the abradingsurface or the disk.